Electrified vehicles (EVs) reduce carbon emissions and fuel costs by providing an electric propulsion system that can either assist, as in the case of a hybrid electric vehicle, or replace, as in the case of an all-electric vehicle, a gasoline-powered combustion engine. However, its power electronic devices generate large noise voltages, a portion of which can propagate through an EV transaxle and appear externally on a half-shaft, wheels or other vehicle structures that have a capacitance to earth. When such noise propagation occurs, a portion of the noise voltage can be induced on the vehicle body, and interfere with radio reception at the vehicle. A vehicle radio antenna is designed to detect the voltage difference between its ground reference, which is typically the vehicle body, and the surrounding external environment. A voltage on the vehicle body will be detected by the antenna and provided to the radio receiver. As a result, a radio listener may hear static, whistles and/or ringing sounds that can vary in pitch. Unfortunately, this type of radio interference can be difficult to mitigate by conventional means.
A previous attempt to prevent shaft-coupled interference at a radio receiver of an electrified vehicle included the installation of brushes to ground the half-shaft to a motor case. However, because brush installation requires space in the transaxle for the brushes, and the addition of a removable cover with gaskets to allow access for maintenance, it fails to provide a simple, low-cost interference mitigation solution.